遺失[ishitsu] loss
遺失物[ishitsubutsu] lost article
一失[isshitsu] disadvantage (defect, error)
一得一失[ittokuisshitsu] gaining some and losing some
栄養失調[eiyoushicchou] malnutrition

過失[kashitsu] error
見失う[miushinau] to lose sight of
失う[ushinau] to lose
失する[shissuru] to lose
失せる[useru] to disappear

威権[iken] authority
永子作権[eikosakuken] perpetual land lease
永住権[eijuuken] permanent residence
越権[ekken] going beyond authority
王権[ouken] royalty

権殿[gonden] temporary shrine (houses the object in which the deity resides when main shrine is under repairs)
加入権[kanyuuken] NTT permission-to-procure-a-phone-line
既得権[kitokuken] vested rights
棄権[kiken] abstaining from voting
棄権者[kikensha] non-voter